Thread-clamp for shoe-sewing machines.



H. A. BALLARD.

THREAD CLAMP FOB SHOE SEWING MACHINES. APPLICATION FILED 3.23, 1909.

1,127,71 9. Patented Feb. 9, 1915.

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THREAD CLAMP FOR SHOE SEWING MACHINES.

APPLXCATION FILED JAN28L19O9.

1,127,719. Patented Fe b.9,1915.

2 SHEETS-SHEET 2.

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. BARBIE A; B LLABD, on BOSTON, A SACHUSETTS, AssIGNon To m Taro. COMPANY, or SOUTH BOSTON, MASSACHUSETTS, A CORPORATION ormnw, JERSEY.

THnEAn-cLAMr non SHOE-SEWING MACHINES.

2 I Application filed'lanuary 28, 1909. Serial No. 474,669.

To all: whom it may piwem Be it known hat I, \HARRIE State of. .Massachusetts, have invented cer- 5 tain new iand useful Improvements in Thread-Clamps for Shoe-Sewing-Machines,

of which the 'following is a specification. This invention-relates to shoe sewing machines, and has for, its object to provide thread-locking means, in connection with a presserfoot adaptedmo automatically compensate for sudden variations in the thickness of thework by supplyinga relatively greater quantity of thread-for an increasing ,15 thickness of work, and 'a' correspondingly smaller quantity'of thread for a decreasing thickness of work. 'The-invention: is-embodied ina pain of cooperative members adapted to clamp the thread between the "goneedle and supply, said members being upon a' lever which carries a mounted presserfoot, these clamping members are therefore moved by'said lever toward and from a thread guide in accordance with'varig5 ations in the thickness of the work. The

clamping members are movedtoward the thread guide when the thickness of the work increases, and away from the thread guide when the thickness of the work decreases, thereby giving up ordrawing back-a .qllantity'of the needle thread.' The'efiect 10f so arranging and, actuating the thread clampi'ng members is to'eliminate to a greater ex- I tent the liability- 20f"breaking the needle thread. I

Of the accompanying drawings" l wl 'ieh illustrate one" form in which the invention may be embodied, Figure'l represents ,a'l'eft \aislelevationbf the operating head "of a S vertical sectionthroughftlie! head. Fig, 5 represents an elevat on of 'the means for actuating the thread-clampingmembers] The same. referena I, H the same parts where r. theyoccnr.

t s eiii eeid i wiihe Specification of Letters Patent.

7 A. BALLIARD, of Boston, in the, county of ,Sufl'olk and characters. mamas":

Patented mi; 9, 1915.

present invention to a shoe sewing machine, t may be stated that the machine herein illustrated comprises ahead or fra1ne 10, a cam shaft 11 journaled therein and stitchforming mechanismincluding a needle 12,

an awl 13, a rotary shuttle l h'a looper 15, a thread finger 16, a loop spreader 17, their actuators hereinafter described and other necessary instrumentalities.

. The needle thread a may be drawn from any suitable source of 'su'pply preferably at the rear of the machine and passes over a tension device 18 and suitable take-up rolls 19, 20 and 21 before engaging the needle.

The take-up roll 21 in this form'of machine is mounted on the free end of'an oscillatory arm while the take-up roll 20 is relatively stationary though preferably yielding, and the roll 19 which is in efiectfmerelyaguide :{rollis preferably stationary, and mounted upon a stud extending from thetrame. 22 represents a stationary worlflrest and 23 represents a presserfoot movable toward 5 and from the work rest and adapted to cooperate therewith in clamping, thelwork a: as shown by v.Fig. 3. The pres'serfoot is mounted upon a lever 24 having a; fulcrum at 25, and is normally forced, toward the work rest by means of a spring 26' of which -one'end 'is' connected to afixturefand the other end to the rear of the presserfoot lever. By this means continual? pressure of the presserfoot upon the work is'inaintained, and this is preferably rendered positive or non-yielding during the operation of the stitch-forming mechanism by flfiyfsuitable means which need not be describedQjIt will 7 be, sufiicient to state that .the' jpresserfoot .lever is adapted to yield duringth'e feeding of the work.

"The needle and awl are mounted respectively upon a needle carrier 27 and an awl carrier28. These earriers'are here shown as adapted to oscillate abojuta common axis 29, but the awl carrier is adapted to mom longitudinally of its axisjor thepurp'ose of feeding the work to the needle. For-"this purpose the awl carrier is 'moijlntedfupon an arm .30, see Fig. 4', which extends] forwardly 1 from a reciprocatory carriage not], shown, *but' which is adapted to be .actuated by i'means, of a lever 31 cooperating with. an appropriate cam upon the cam,-.shaft 11.

The thread clamping members are arranged so as clamp the thread between-the tension 18 and theguide roll 19 as shown by Figs. 1 and 4. These members comprise a grooved roll 32 over which 'the thread is adapted to pass, and a complemental sliding member 33 adapted to cooperate therewith to clamp the-thread. The roll 32 and slide 33 are moun upon the presserfoot lever 24 at the rear of the fulcrum 25, and are adapted by reason of such arrangement to move toward the roll 19 when the presserfoot is moved away from the work rest, and on the other hand to move away from the roll 19 when the presserfoot is moved toward the work rest. The effect of such movement of the thread clamping members is to give an additional quantity of thread to the needle when the presserfoot is moved away from the work rest, a V to take away a quantity of thread from the needle when the presserfoot is moved toward the work rest.

The slide 33 is mounted in guides 34 and is provided with a stud or-projection 35 which occupies a slot 36 formed in an arm 37. The slot 36 is curved so that, when the arm is in the position shown,-it is concentric with relation to the fulcrum 25 in" order to enable the presserfoot leverto move about its fulcrum without disturbing the relation of the slide 33 with its complemental clamp-.

ing member 32. The arm 37 is aifixedupon a rock shaft 38 which has a suitable bearing in the head or arm 10.- The rock shaft. 38 is also provided with an arm 39 by which it is automatically actuated. The-arm39 has in its free end a cam roll 40 which occupies a groove 41 formed in a cam disk 42 mounted on the shaft 11. The width of the groove 41 is considerably greater'than' the diameter of the roll 40 for the purpose of permitting movement of the roll independently of the cam for a purpose hereinafter explained. The arm 39 is one arm of a lever which has an oppositely extending arm 43. A spring 44 contained in the socket 45 on the frame engages the arm 43 and forces it in a direction tending to hold the cam roll 40 in engagement with the outer wall of the groove 41. The roll 40 however is so adjusted that it is prevented from ngaging the outer wall of the groove, with the exceptions hereinafter stated, by reason of the coiiperative engagement of the clamping member 33 with the member 32. For the purpose of retracting the member 33 so as to release the thread, the outerwall of the. groove 41 is provided with cam portions 46 and 47 which are adapted to engage-the roll 40. v

Referring now to the stitch-forming mechanism, the operations of the shuttle 14,-

the looper 15, the thread finger 16 and the loop spreader 17 may be briefly described. The shuttle is contained in a shuttle race 48 in which it is driven continuously in the direction of the arrow shown in Fig. 2. The shuttle race is cut away at the point nearest the needle so as to provide for the en\trenc. of a loop 5 of needle thread into tin. 2i

of the nose 49 of the shuttle, The shiittie is driven by a finger 50 on the forward end of a shaft 51 which may be driven by any appropriate means on the cam shaft 11. Thelooper 15 is mounted'upon a carrier 52, (see Fig. 1), and is actua ed so as to lay the thread a about the barb of the needle when the needle extends thro gh the work so that its barb is below the" work rest 22. The thread finger 16is initially in front of the needle thread between the looper and the work rest, and is movable from front to rear for the purpose of drawing a quantity of thread from the take-up which it subsequently gives back to the needle while the latter is receding to draw the thread through the work. The thread finger is at one end of a slide 53 which has a pin and slot connection with a lever or actuator 54 arranged in coiiperative, engagement with a suitable cam on the shaft 11. The loop spreader 17 is atthe free end of an arm 55 mounted upon a rock shaft 56. The-rock shaft carries an arm 57 at the free end of which is a roll 58 adapted to engage the periphery of the cam disk 42. A spring 156 acting on the rock- 'shaft 56 serves to keep the roll 58 in en-' gagement with the cam which has a bulging portion 59.. The-portion 59 imparts movement to the loop spreader 17 which causes the latter to enter a newly formed loop being drawn upwardly by the needle. The

loop spreader opens the loop as shown by cam portion 46 to release the thread as the shuttle completes its thread-pulling movement. In view of this operation, the takeup' lever 60 is not depended upon to set the stitch, but is employed'for taking up the slack in the .needle thread as it is released by the shuttle. The cam portion 46 does not engage its roll 40 until the preceding stitch has been set by the thread-pulling movement 5 .1

of the shuttle, but it does engage the roll so as to release the thread before the nose 0. the shuttle reaches its highest point. After this releasing of the thread, the remaininv upward movement of the nose 49 has til? 3 effect of drawing an additional supply of thread for the next stitch, and after tne shuttle has passed its highest point, the take-up arm 60 is actuated so as to draw off the excess thread for the next stitch. The

was; is g d arm 43 is extended sufficientl to form a active thread-clampin members, means arhandle by which the rock sha t 38 may be ranged to move one 0 said thread-clamping manually moved for the purpose of retractmembers toward and from the other to ing the clamping member 33 at any time it clamp and release the thread, and means arshould be desired to so release the thread. ranged to more said threadclamping mam Having thus explained the nature of the to give up and take back thread on the invention, and described a way of constructincrease and decrease, respectively, of the ing and using the same, although without atthickness of the work, the Jet-mentioned tempting to set forth all of the forms in means being arranged to ciamp the thread which it may be made, or all of the modes at the same rilativc stage in successive cycles of its use, I declare that What I claim is 1- regardless of the position of said clamping '10 1. In a sewing machine of the character member. described,stitch-forming mechanisnnapress in a. machine ofthe character erfoot carrier, ead described, form. mechanism, c0- moved bacl e ire iz'icmbers, means a1. give up and takei'ir i, read o. the i *1 said thread-clamping '75 and decrease resp *iiieiy, of the thickness H from the other to of the Work, and means arranged to operate clamp and reiease the thread, and means atsaid thread lock to lock and release the ranged to move said thread-clamping memthread, said means being arranged to keep bers to give up and take back thread on the the thread lock in release position for as increase and decrease, respectively, of the long a time for thin work asfor thick work. thickness of the work, the first-mentioned 2. In a sewing machine of the. character means being arranged to release the thread described, stitch forming mechanism, a at the same relative stage in successive cycles presserfoot carrier, a thread lock arranged regardless of the position of said clamping to be moved back and forth by said carrier member. to give up. and take back thread on the in- .7. In a sewing machine of the character crease and decrease, respectively, of the described, stitchforming mechanism, a. thickness 6f the Work, and means arranged Work support, a presserfoot and carrier to operate said thread lock to lock and re therefor, a spring arranged to act on said lease the thread, said means being arranged carrier to keep said presserfoot against the to keep the thread lock in looking position n'ork a thread lock carried by said carrier for as long a time for thick Work as for thin and thereby movable to give up and take Work. back thread on the increase and decrease, re-

3. In a sewing machine of the character spectively, of the Work, a member arranged described, stitch forming mechanism, a to operate said thread lock, and means conpresserfoot carrier, a thread lock arranged necting said operating member and thread to be moved back and forth by said carrier lock to preserve uniform timing of said to give up and take back thread on the in thread look by compensating for different crease and decrease, respectively, of the positions of the latter. thickness of the Work, and means arranged 8. In a sewing machine of the character to operate said thread lock to lock and redescribed, stitch-forming mechanism, a lease the thread, said. means being arranged presserfoot carrier, a thread lock arranged to maintain uniform timing of the thread to be moved back and forth by said-carrier lock regardless of the position of the latter. to give up and take back thread on the ine. In a sewing machine of the character crease and decrease, respectively, of the described, stitchforming mechanism, a thickness of the work. and means arranged presserfoot carrier, a thread lock arranged 'to operate saidthread lock to lock and re to be moved back and forth by said carrier lease the thread, said means being arrange to give up and take back thread on the into time the operation of said thread lock increase and decrease, respectively, of the dependently'of variations in the position of thickness of the work, and means arranged to operate said thread lock to lock and release the thread, said means being arranged to keep the thread lock in locking position the samelength of time in successive cycles, regardless of the position of the thread lock:

5. In a. sewing machine of the character described, stitcl forming mechanism, co-

the thread lock.-

In testimonywhereof I ha e aflixed my signature, in presence of two Witnesses.

HARRIE- A. BALLARD.

Witnesses Geo. T. ARMSTRGNG, M. E. Carma. 

